unitsize(1cm);

real a = 2;
real b = 1;
real cx = 0;
real cy = 0;
pair c  = (cx, cy);
path e1 = ellipse(c, a, b);

currentpen = currentpen + fontsize(6pt);

string s_c = "(" + format("%.1f",c.x) + "," + format("%.1f",c.y) + ")";
draw(e1);
dot(c, L=s_c, W);

currentpen += blue;

draw(c--(a, c.y), arrow=Arrow, L="a");
draw(c--(c.x, b), arrow=Arrow, L="b");

